Automatic stoker



Sept. 7, 1937. w. M. DUNCAN AUTOMATIC STOKER Filed July 16, 1934 SPEEDCHANGE GEARING- Patented Sept. 7, 1937 UNITED STATES PATENT OFFIQEAUTOMATIC STOKER William M. Duncan, Alton, 111.

Application July 16, 1934, Serial No. 735,354

6 Claims.

This invention pertains to stokers of the type employing a blast ofsteam or the like to deliver the fuel to the fire bed.

I One of the objects of this invention is to k provide a stoker of thistype which will deliver the fuel in such a manner as to form a uniformbed over the entire grate.

Another object is to provide such a stoker in which the action may beadjusted so as to vary the manner in which the fuel is distributed.

Another object of this invention is to provide novel mechanism by whichthe movement of the distributing parts may be adjusted and controlled.

Further objects will appear from the following description taken inconnection with the accompanying drawing in which:-

Figure l is a side view partly in section of a stoker embodying thisinvention;

Figure 2 is a section taken about on line-22 of Figure 1;

Figure 3 is an enlarged detail of Figure 2; and Figure 4 is a detailofFigure 1, showing the nozzle extended and the deflector plate inexpanded relation with the blast tube and the nozzle.

In the following description, that end of the apparatus which isprojected into the'furnace is considered the forward end for thepurposes of the description and claims.

In accordance with this invention the fuel is injected into the furnaceby being passed through an injection tube'by means of a steam jet. Theend of the tube is provided with a nozzle which maybe directed towarddifferent parts of the furnace grate and is adapted to deflect the fueland direct it to corresponding parts of the grate. Mechanism is providedfor moving the tube and its nozzle progressively in a definite cycle sothat thefuel is deposited on different parts of the grate in aprogressive manner so as to cover the entire grate.

Referring now .to the drawing, designates the furnace wall havinganopening 2 through which the injection tube may enter the furnace. Thegrate is indicated at 3.

A suitable support 4 is provided which may be mounted outside thefurnace adjacent the wall 1 so as to support the stoker mechanism. Inthe embodiment illustrated the support 4 is constructed as a frame workof angle iron.

Mounted in the upper part of the frame .work 4 is a pair of supportingrings..5. These are each provided on its inner surface with a. rib ortrack '6. A blast tube 1 is provided with rollers 8 supthe tube 1.

ported in the rings 5 and having grooves adapted to run on the tracks 6.In this manner the tube 1 is supported in the rings 5 for rotary rockingmovement on its axis. Secured to the tube 7 is an arm 9 by means ofwhich the tube may be rocked on its-axis.

In order to actuate the tube a motor I8 is connected by a belt I! todrive the shaft l2 carrying a pulley I3 connected by a belt I l to drivea shaft l5 of a speed changing mechanism it. The speed changer I6 hastwo low speed shafts, one of which I1 is connected to operate themechanism for rocking the tube. The shaft ll carries a crank oreccentric i8 having a strap i9 on the end of a connecting rod 20. Therod 25 is adjustable in length in any suitable manner and carries at itsupper end a fork2l pivoted to a collar 22 adjustable along an arm 23pivoted on a shaft 24. The arm 23 carries a pawl 25 engaging a ratchetwheel 26 on the shaft 24. The ratchet wheel 26 is provided with aplurality of perforations 21 providing sockets for a pivot pin 28 for alink 29 pivoted at its other end to the free end of the arm 9.

Bythe operation of this mechanism the eccentric l8 acting through therod 20 rocks the arm 23 about the shaft 24. This arm acting through thepawl 25 rotates the ratchet wheel 26 which in turn provides a crankmechanism for reciprocating the link 29. The link 29 swings the arm 9 upand down and thereby rocks the tube in its bearing rings 5. The throw ofthe crank mechanism is adjustable by changing the pivot pin 28 todifferent holes 21, said holes being located at different radii withrespect to the shaft 24. By adjusting the collar 22 along the arm 23 theextent of movement given by the pawl 25 to the ratchet wheel 26 at eachstroke may be adjusted. Accordingly, both'the extent of the rockingmovement of the blast tube and also the rapidity of such movement may beadjusted at will.

The tube 1 extends through the opening 2 to the interior of the furnaceand is provided at its inner end with a nozzle 3| pivoted at 32 on abracket 33 carried by the tube 7. This pivotal mounting provides thatthe nozzle 3| may be. swung outwardly or inwardly so as to direct theblast toward any portion of the grate 3. The nozzle 3| has a loosesection 34 pivoted at 35 to the nozzle itself. -The rear portion of thesection 34 is provided witha roller 36 adapted to run in a groove3'lextending along theupper portion of The nozzle 3| is provided at theinner end thereof with a pin 39. This pin provides a pivotal connectionto an adjustable link 30 which link is pivoted at M to a bracket 42extending forwardly from an actuating ring 43. The ring 53 surrounds thetube l and is provided with grooved rollers 44 running on tracks 55mounted to extend along the tube 1 at the rear portion thereof. movingthe ring 43 rearwardly along the tube 1 the link acts to pull on the pin39 thereby tilting the nozzle 3| upwardly on its pivot 32. During suchmovement the loose section 314 hinges at 35, the roller 3t movingrearwardly in the groove 3?. The link M and its connections may beduplicated on the opposite side of the tube l. The loose section 34 isprovided with a pin 38 adapted to engage a hook ll on the end of thelink 40, which prevents said section from tilting up on the pivot 35.

This arrangement provides a variable telescopic engagement between thetube and its nozzle so as to insure proper functioning in all positions.The section 34 takes an expanded position with reference to the nozzle3i when the latter is tilted upwardly.

The actuating ring 43 is operated by the following mechanism. The secondlow speed shaft of the speed changer I6 is indicated at 46, see Figure2. This shaft carries a crank 4'? connected by an adjustable link #18 toa collar 49 adjustable along an arm 50. The arm 50 is fixed to arockshaft 5! journaled in suitable bearings on the frame 4 and carryinga pair of arms 52 of a fork embracing the ring 43 having at their upperends inwardly directed pins engaging in a groove 53 in the actuatingring 83. It will be seen that by this mechanism the operation of theshaft 56 will act through the link 48': and the arm 56 to rock the shaft5i. Said shaft in turn rocks the arms 52 and said arms operate to movethe ring 43 rearwardly and forwardly along the tube 1, the rollers 44moving along the tracks 45 during such movement. The extent of thismovement can be adjusted by adjusting the collar 49 along the arm 50.

The mechanism just described operates to tilt the nozzle 3! on its pivot32. This movement changes the direction ofthe nozzle 3! from front torear of the grate 3 so that fuel issuing therefrom will be depositedprogressively along the depth of the grate. The rocking movement of thetube 1 on its axis takes place simultaneously so that as the nozzle 3|is swung forward and reaward, the tube 1 is gradually rocked.Accordingly the successive swings of the nozzle will deposit the issuingfuel along paths progressively spaced from one another laterally of thegrate 3. As these movements take place in a definite cycle, it will beseen that the fuel is deposited progressively along different portionsof the grate so that the entire grate is covered. The regularly repeatedcycles of movement may be so adjusted that a uniform bed of fuel isproduced and maintained on the grate 3. v

In order to propel the fuel along the tube 7 a jet 5 3 for steam or thelike is directed along the tube i from the rear end thereof. This jetmay be connected by a pipe 55 to a suitable source of supply, not shown.

Mounted opposite of the rear end of the tube 1 is a fuel feedingconveyor 56 adapted to receive fuel such asjcoal from a hopper5'l and todeliver the same in front of the jet 54. Theconveyor 56 may be driventhrough a suitable gear box 58 connected by a belt 59 to a suitablespeed controlling device 60 illustrated in the drawing as Theseconnections are such that by of the well known Reeves transmission type,comprising. a pair of V-groove pulleys having flanges oppositelyadjustable to vary the operating radius of a connecting V-belt '55 alsodriven by the motor l0 thru belt H and shaft l2. This provides forsuitably controlling the rate of feed of the fuel so as to control theaction of the furnace.

In the embodiment illustrated the hopper 57 is designed for coal and isarranged so that the coal is delivered to the blast tube by feeding itso as to cause it to drop in front of the jet 5%, an opening beingmaintained over the coal for the entrance of air to assist in carryingthe fuel through the blast tube and for combustion thereof.

In order to stop the operation of the stoker when the motor I0 isstopped, the steam line 55 valve may be connected with any suitabledevice for closing it automatically when the motor lfl'is g' stopped, asfor instance, a solenoid 6 5, through may be provided with a shut offvalve M. This The blast tube 1 may be provided with perforations l0 nearits rear end, positioned so that the aspirating action of the jet iiiwill draw in air which assists in carrying the fuel along the tube.

Such air is delivered to the fire box with the fuel to take part in thecombustion thereof.

It will be seenthat this invention providesa stoker of simpleconstruction which is effective in operation and flexible in itsadjustment making it adaptable to a variety of firing conditions.

The tube 7 is rockable upon its axis and is provided with an articulatednozzle movable on the tube itself. nozzle may be varied relatively toeach other so as to vary the cycle of movement of the nozzle in order tocontrol the manner in which the fuel is distributed upon the grate. Theactuating mechanisms are simple and easily adjusted. The entire stokeris so arranged that it may be built up as a unit and applied to anyexisting furnace by simply mounting the same in front of the furnace andinserting the blast tube through a suitable opening in the furnace wall.

While this stoker has been described as a unitary device it will beunderstood that individual features or sub-combinations thereof may beuseful by themselves without reference to other features or the completecombination'and it is understood that the employment of such individualfeatures or sub-combinations is contemplated by this invention andwithin the scope of the appended claims.

It is obvious that various changes may be made, within the scope of theappended claims, in the details of construction without departing fromthe spirit of this invention. It is to be understood, therefore, thatthis invention is not limited to the specific details shown and/ordescribed.

Having thus described the invention, what is claimed is: i

1. In a stoker of the character described, a blast tube adapted to beextended into the furnace and a nozzle tube hinged at its lower edgehinged to said body portion and freely engaging The movements of thetube and the said blast tube at its free end to permit swinging saidnozzle tube through sub s tantia llyraright porting angle.

2. In a stoker of the character described, a blast tube adapted to beextended into the furnace at a substantial elevation above the gratethereof and a nozzle tube hinged at its lower edge to said blast tube,said nozzle tube comprising a main body portion and an upper wallportion hinged to said body portion and freely engaging said blast tubeat its free end to permit swingin a said nozzle tube downwardly at ananglesuch as to deposit the fuel at the front of thegfate.

3. In a stoker of the character described, a blast tube adapted to beextended into the furnace, a nozzle tube at theinner end of said blasttube arranged to,.-forfn an extension thereof, means swingablysupporting said nozzle tube for movement to various positions relativeto said blast tube, said nozzle tube having a wall portion thereof freefor movement relative tosaid nozzle tube, means swingably supportingsaidallportion adjacent the juncture of said nozzle and said blast tube, andmeans on said wall portion engaging one of said tubes adapted toposition said wall portion to form with said tubes a substantiallycontinuous tubular guide for the fuel in all positions of said nozzletube.

4. In a stoker of the character described, a blast tube adapted to beextended into the furnace, a nozzle tube at the inner end of said blasttube arranged to form an extension thereof, means swingably supportingsaid nozzle tube for movement to Various positions relative to saidblast tube, a wall portion arranged in continuity with said nozzle tubeand free for movement relative to said nozzle tube, means swingablysupand means on said wall portion engaging the other of said tubesadapted to position said wall portion to form with said tubes asubstantially continuous tubular guide for the fuel in all positions ofsaid nozzle tube.

5.,In a stoker of the character described, a blast tube adapted to beextended into the furnace, a nozzle tube swingably supported at theinner end of said blast tube for movement to various positions inangular extension of said blast tube, and a wall section movably mountedin continuity with said tubes adjacent the juncsaid wall portion on oneof said tubes,

ture thereof and means engaging said tubes to 5 position said section inbridging relation thereto for guiding the blast from said blast tube tosaid nozzle tube.

6. In a stoker of the character described, a

blast tube'adapted to be extended into the furnace, a nozzle tube at theinner end of said blast tube, means swingably supporting said nozzletube for movement to various positions relative to said blast tube inangular extension thereof,

a wall section free for movement relative to said tubes, means swingablysupporting said section on one of said tubes, said section being incontinuity with one of said tubes adjacent the juncture thereof, andmeans on said section engaging the'other of said tubes, said supportingand engaging means being constructed and arranged to position saidsection intermediate said tubes to provide a guide adapted to direct theblast from said blast tube to said nozzle tube.

WILLIAM: M. DUNCAN.

